Concrete insert

ABSTRACT

A concrete insert having a housing with an elongate centre portion. Longitudinal sides depend inwardly and have edge surfaces. Longitudinal flanges depend transversely from longitudinal sides and diverge. Lateral ends depend inwardly and have mating surfaces on inside surfaces of the lateral ends for mating substantially flush with the edge surfaces which support the lateral ends and flanges. Lateral flanges depend transversely from lateral ends and diverge. The concrete insert includes a nut box insert comprising a bottom wall mounted in the housing for sealing an open bottom of housing and for sealing the gaps between the edge surfaces and the mating surfaces. The housing and the nut box insert forming a nut box, with a nut slidably mounted in the nut box, the nut box for constraining rotation of the nut for the threaded hole in the nut to receive a threaded fastener through an access slot in housing.

FIELD OF THE INVENTION

This invention relates to an improved concrete insert for attaching concrete panels to buildings.

BACKGROUND OF THE INVENTION

Current building practices in North America and elsewhere utilize pre-cast concrete wall panels to form the perimeter walls of a building. A plurality of concrete inserts are embedded in the concrete panels when they are pre-cast, such that a substantially flat elongate centre portion of each concrete insert is located flush with the intended inside surface of the pre-cast concrete wall panels. An access slot through the elongate center portion of each concrete insert provides access for an attaching bolt to connect with a captive nut, located in an enclosed concrete free channel under the elongate centre portion, the enclosed channel commonly referred to as a “nut box”. The nut is selectively positioned under the access slot to receive the inserted attaching bolt. An attaching bolt is typically first inserted through an aperture in a structural member of the building and then secured to the captive nut in the nut box of the concrete insert pre-cast in the concrete wall panel, thus securing the pre-cast concrete wall panel to the structural member of the building, to form the perimeter walls of the building.

Concrete inserts typically have a metal housing formed from a single sheet of plate steel, being bent into an inverted “U” shaped or “V” shaped channel with an open bottom and open ends. The elongate center portion forms the valley of the inverted “U” or “V” shaped channel and opposing longitudinal sides depending from the elongate center portion form the sides of the inverted “U” or “V” shaped channel. The inverted “U” or “V” shaped channel of the nut box only allows the nut to be displaced longitudinally under the open slot in the nut box, and prevents the nut from rotating when an attaching bolt is threaded into the nut.

In order to increase the pull out resistance of such concrete inserts the longitudinal sides of the concrete inserts depending from the elongate center portion may terminate at transverse opposing longitudinal flanges mutually diverging from each other parallel with the intended inside surface of the pre-cast concrete wall panels in which the inserts are to be embedded. However such prior art concrete inserts may still fail with the opposing longitudinal flanges being drawn through the cavities in the concrete panels formed during the casting of the concrete about the concrete insert or by local breaking away of the concrete adjacent the longitudinal flanges.

Earlier attempts to improve pull-out resistance of concrete inserts include U.S. Pat. No. 5,890,340 to Kafarowski who recognized that opposing inwardly diverging end surfaces of two opposing longitudinal sides of a concrete insert provide some additional pull out resistance. However the additional end pull out resistance provided by Kafarowski is still limited.

While various patents such as U.S. Pat. No. 1,768,246 to Gaddis and U.S. Pat. No. 2,133,134 to Davis and US Patent No. Des 406,524 to Stevenson et al utilize end flanges, said flanges are arranged flush with the intended inside surface of the pre-cast concrete wall panel in which the concrete inserts are to be embedded, for the sole purpose of nailing or otherwise attaching the concrete inserts to the form-work before the concrete panels are cast, and were not designed to provide any pull out resistance.

Accordingly, there exists a need for a concrete insert having further means of pull out resistance.

SUMMARY

The invention provides for the addition to prior art concrete inserts of structural end flanges which end flanges may comprise form mounting holes for nailing, screwing or otherwise attaching the concrete insert to forms before the concrete panels are cast. Structural end flanges may also comprise stud apertures for the attachment of studs or studs fixedly attached to the end flanges. Structural end flanges are attached to structural ends of the concrete inserts which are attached to and form part of a housing, and are supported by the housing which in turn support the structural end flanges and resist deformation of the structural ends and structural end flanges in response to pull out pressure. Structural ends may be supported by the structural sides by structurally connecting the ends to the sides such as by welding, or other forms of structural attachment, which may or may not sealably attach the ends to the sides. If structural ends and structural sides are sealably attached such as by welding, then there are no gaps between the ends and sides which require sealing to keep concrete out of the nut box. If structural ends and structural sides are non-sealably attached then gaps between the ends and the sides will need to be separately sealed. Alternatively, structural ends, which support structural end flanges, may be supported by the structural sides of the housing without sealably attaching the ends to the sides resulting in gaps therebetween which must be sealed to keep concrete out of the nut box during casting. The housing may, but need not, be made from a blank of a single sheet of plate metal and bent along the desired bend lines or edges to achieve the desired shape of housing and to cause the structural ends to be supported by the structural sides of the concrete insert, which structural ends in turn support the structural end flanges. In particular such non-sealed support of the structural ends, which in turn support the structural end flanges, has the significant advantage of avoiding the cost of mechanically sealing the ends and sides of the metal housing, such as by welding, which provides significant support to the structural end flanges. In this specification the word structural in relation to the ends and sides and end flanges and side flanges of the housing mean load bearing. All sides and ends and side flanges and end flanges of the invention herein shall be taken as load bearing unless the contrary is intended.

In one aspect the invention includes a housing having lateral end flanges connected to lateral ends extending from an elongate centre portion of a concrete insert, the elongate centre portion for substantially flush mounting with the inside surface of a concrete panel, the lateral ends depending inwardly (into the concrete panel) in parallel or mutually divergent relation wherein the lateral ends are supported by the edge surfaces of the longitudinal sides of the concrete insert. In another aspect of the invention the elongate centre portion, longitudinal sides, longitudinal flanges, lateral ends and lateral flanges of a housing for the concrete insert are made from a blank of plate metal, preferably plate steel, wherein the longitudinal sides and longitudinal flanges and lateral ends and lateral flanges are made by bending the blank such that inner mating surfaces, being a part of the inside surface of the lateral ends, are supported by the edge surfaces of the corresponding longitudinal sides. This includes mating surfaces along the inside surface of lateral ends located substantially flush with edge surfaces of the longitudinal sides wherein gaps between the mating surfaces and the edge surfaces of the plate metal forming the housing are sealed by means other than the housing to prevent wet concrete present during the forming of concrete panels from entering the nut box within the housing. Such sealing may be effected by the insertion of a nut box insert into the open bottom of the housing or by other means, such as by the application of sealing agent. The sealing of the said gaps does not preclude some wet cement passing through the gaps into the open bottom of the housing provided that no concrete enters the cavity defining the nut box. In one aspect the lateral flanges are inward of the elongate centre portion. In another aspect the lateral flanges are co-planer with or inward of the longitudinal flanges. In another aspect lateral flanges are located inwardly at least as deep as the bottom wall of the nut box insert and not deeper than rebar apertures in the longitudinal sides of the concrete insert. Lateral flanges are arranged transverse to lateral ends providing significant resistance against deformation to both the lateral flanges and the lateral ends when the mating surfaces of lateral ends are supported by the edge surfaces of the longitudinal sides.

In one aspect the invention provides a concrete insert for casting in a concrete wall panel having an inside surface for attachment to a building the concrete insert having a housing having an elongate centre portion, two opposing longitudinal sides, two opposing lateral ends, two opposing longitudinal flanges, and two opposing lateral flanges. The elongate centre portion, bounded by opposing outer longitudinal bend lines and by opposing outer lateral bend lines, has an outer attachment surface for mounting the elongate centre portion substantially flush with the inside surface of the concrete wall panel, the elongate centre portion defining a longitudinally oriented access slot. The opposing longitudinal sides depend inwardly from the opposing outer longitudinal bend lines to opposing inner longitudinal bend lines and have opposing edge surfaces defined by the elongate centre portion, the longitudinal flanges and the thickness of the longitudinal sides. The opposing longitudinal flanges depend from opposing inner longitudinal bend lines transversely to the opposing longitudinal sides and extend in mutually divergent relation. The opposing lateral ends depend inwardly from the opposing outer lateral bend lines to the opposing inner lateral bend lines and have opposing mating surfaces on the inside surfaces of each of the lateral ends for mating substantially flush with the opposing edge surfaces of each longitudinal side. The opposing lateral flanges depend from the opposing inner lateral bend lines transversely to the opposing lateral ends and extend in mutually divergent relation.

In addition to the housing the invention provides for a nut box insert comprising a bottom wall mounted in the housing for sealing an open bottom of the housing, the open bottom defined by inside surfaces of the opposing longitudinal sides and inside surfaces of the opposing lateral ends and for sealing the gaps between the edge surfaces and the mating surfaces, the housing and the nut box insert comprising a nut box, with a nut defining a threaded hole slidably mounted in the nut box, the nut box for constraining rotation of the nut for the threaded hole in the nut to receive a threaded fastener through the access slot for attaching the concrete wall panel to the building.

In another aspect the elongate centre portion is substantially flat and the opposing longitudinal sides are substantially parallel to each other and substantially perpendicular to the elongate centre portion. In another aspect the elongate centre portion is substantially flat and the opposing longitudinal sides depend inwardly from the opposing outer longitudinal bend lines in mutually divergent relation. In another aspect the opposing lateral ends are substantially parallel to each other and substantially perpendicular to the elongate centre portion. In another aspect the opposing lateral ends depend inwardly from the opposing outer lateral bend lines in mutually divergent relation. In another aspect the lateral flanges are intermediate the elongate centre portion and the longitudinal flanges. In another aspect the opposing longitudinal sides each have at least one rebar aperture outwardly from the opposing longitudinal flanges and the opposing lateral flanges are located inwardly from the elongate centre portion and outwardly from each rebar aperture. In another aspect the opposing longitudinal flanges and the opposing lateral flanges are substantially parallel with the elongate centre portion. In another aspect the housing is made of plate steel. In another aspect the plate steel is between approximately ⅛ inch and ¼ inch thick. In another aspect the plate steel is approximately 3/16 inch thick. In another aspect the nut box insert is unitary insert. In another aspect the nut box insert has end walls for sealing the gaps between the edge surfaces and the mating surfaces. In another aspect the nut box insert has side walls and end walls that extend from the bottom wall of the nut box insert to an inner surface of the elongate centre portion. In another aspect the nut box insert further comprises a top wall defining a nut box insert slot in register with the access slot, the nut box insert being resiliently deformable for loading the nut box insert with the nut before the nut box insert is mounted in the housing. In another aspect the nut box insert is a compound insert. In another aspect the bottom wall of the nut box insert carries one or more a resilient layer for sealing the open bottom of the housing and for sealing the gaps between the edge surfaces and the mating surfaces. In another aspect the nut box insert is held in place by one of the group consisting of supports formed in the longitudinal sides, supports formed in the lateral ends, fastening to the lateral flanges, a friction fit, and gluing. In another aspect the nut is held in biasing contact with the nut box for selectively positioning the threaded hole in the nut along the access slot.

In another aspect the nut is held in biasing contact with the nut box by a nut biasing spring between the nut and the bottom wall of the nut box insert. In another aspect the nut is held in biasing contact with the nut box by the resilient layer. In another aspect each opposing lateral flange comprises at least one form mounting hole. In another aspect each opposing longitudinal flange comprises at least one form mounting hole. In another aspect the longitudinal flanges or lateral flanges comprise one or more stud apertures. In another aspect the longitudinal flanges or lateral flanges comprise one or more studs extending inwardly from the longitudinal flanges or the lateral flanges. In another aspect the housing is made from a blank of plate metal which forms the housing into a predetermined shape when the blank is bent along outer longitudinal bend lines, outer lateral bend lines, inner longitudinal bend lines and inner lateral bend lines. In another aspect the housing is made according to a method comprising the following steps:

-   -   1. cut the blank out of the plate metal into the two dimensional         shape necessary to form the housing into the desired three         dimensional shape;     -   2. bend the blank along the inner longitudinal bend lines;     -   3. bend the blank along the inner lateral bend lines;     -   4. bend the blank along outer longitudinal bend lines;     -   5. bend the blank along outer lateral bend lines;     -   6. punch the access slot, rebar apertures form mounting holes         and stub apertures in the blank.

In another aspect the invention provides a concrete insert for casting in a concrete panel having an inside surface for attachment to a building, the concrete insert having a housing having an elongate centre portion, two opposing longitudinal sides, two opposing lateral ends, two opposing longitudinal flanges, and two opposing lateral flanges. The elongate centre portion, bounded by opposing outer longitudinal bend lines and by opposing outer lateral bend lines, has an outer attachment surface for mounting the elongate centre portion substantially flush with the inside surface of the concrete panel, the elongate centre portion defining a longitudinally oriented access slot. The opposing longitudinal sides depend inwardly from the opposing outer longitudinal bend lines to opposing inner longitudinal bend lines. The opposing longitudinal flanges depend from opposing inner longitudinal bend lines transversely to the opposing longitudinal sides and extend in mutually divergent relation. The opposing lateral ends depend inwardly from the opposing outer lateral bend lines to the opposing inner lateral bend lines. The opposing lateral flanges depending from the opposing inner lateral bend lines transversely to the opposing lateral ends and extending in mutually divergent relation. The longitudinal sides and lateral ends define gaps therebetween, with means for sealing the gaps between the longitudinal sides and the lateral ends. This aspect of the invention also includes a nut box insert comprising a bottom wall mounted in the housing for sealing an open bottom of the housing, the open bottom defined by inside surfaces of the opposing longitudinal sides and inside surfaces of the opposing lateral ends, the housing and the nut box insert comprising a nut box, and a nut defining a threaded hole slidably mounted in the nut box, the nut box for constraining rotation of the nut for the threaded hole in the nut to receive a threaded fastener through the access slot for attaching the concrete panel to the building.

In another aspect the means to seal the gaps are independent of the nut box insert. In another aspect the gaps are sealed by welding the gaps closed. In another aspect the gaps are sealed by a sealing agent. In another aspect the gaps are also sealed by the nut box insert. In another aspect the elongate centre portion is substantially flat and the opposing longitudinal sides are substantially parallel to each other and substantially perpendicular to the elongate centre portion. In another aspect the elongate centre portion is substantially flat and the opposing longitudinal sides depend inwardly from the opposing outer longitudinal bend lines in mutually divergent relation. In another aspect the opposing lateral ends are substantially parallel to each other and substantially perpendicular to the elongate centre portion. In another aspect the opposing lateral ends depend inwardly from the opposing outer lateral bend lines in mutually divergent relation. In another aspect the lateral flanges are intermediate the elongate centre portion and the longitudinal flanges. In another aspect the opposing longitudinal sides each have at least one rebar aperture outwardly from the opposing longitudinal flanges and the opposing lateral flanges are located inwardly from the elongate centre portion and outwardly from each rebar aperture. In another aspect the opposing longitudinal flanges and the opposing lateral flanges are substantially parallel with the elongate centre portion. In another aspect the housing is made of plate steel. In another aspect the plate steel is between approximately ⅛ inch and ¼ inch thick. In another aspect the plate steel is approximately 3/16 inch thick. In another aspect the nut box insert is a unitary insert. In another aspect the nut box insert has end walls for sealing the gaps between the longitudinal sides and the lateral ends. In another aspect the nut box insert has side walls and end walls that extend from the bottom wall of the nut box insert to an inner surface of the elongate centre portion. In another aspect the nut box insert further comprises a top wall defining a nut box insert slot in register with the access slot, the nut box insert being resiliently deformable for loading the nut box insert with the nut before the nut box insert is mounted in the housing. In another aspect the nut box insert is a compound insert. In another aspect the bottom wall of the nut box insert carries one or more a resilient layer for sealing the open bottom of the housing and for sealing the gaps between the longitudinal sides and the lateral ends. In another aspect the nut box insert is held in place by one of the group consisting of supports formed in the longitudinal sides, supports formed in the lateral ends, fastening to the lateral flanges, a friction fit, and gluing. In another aspect the nut is held in biasing contact with the nut box for selectively positioning the threaded hole in the nut along the access slot. In another aspect the nut is held in biasing contact with the nut box by a nut biasing spring between the nut and the bottom wall of the nut box insert. In another aspect the nut is held in biasing contact with the nut box by the resilient layer. In another aspect each opposing lateral flange comprises at least one form mounting hole. In another aspect each opposing longitudinal flange comprises at least one form mounting hole. In another aspect the longitudinal flanges or lateral flanges comprise one or more stud apertures. In another aspect the longitudinal flanges or lateral flanges comprise one or more studs extending inwardly from the longitudinal flanges or the lateral flanges. In another aspect the housing is made from a blank of plate metal which forms the housing into a predetermined shape when the blank is bent along outer longitudinal bend lines, outer lateral bend lines, inner longitudinal bend lines and inner lateral bend lines. In another aspect the plate metal is plate steel.

In a further aspect the invention includes a concrete insert for casting in a concrete panel having an inside surface for attachment to a building, having a housing having an elongate centre portion, two opposing sides, two opposing ends, two opposing side flanges, and two opposing end flanges. The elongate centre portion, bounded by opposing side edges and by opposing end edges, has an outer attachment surface for mounting the elongate centre portion substantially flush with the inside surface of the concrete panel, the elongate centre portion defining a longitudinally oriented access slot. The opposing sides extend inwardly from the opposing side edges to the opposing side flanges. The opposing side flanges extend transversely from the opposing sides and extend in mutually divergent relation. The opposing ends extend inwardly from the opposing end edges to the opposing end flanges. The opposing end flanges extend transversely from the opposing ends and extend in mutually divergent relation. The sides and the ends defining gaps therebetween, and means for sealing the gaps between the sides and the ends. This aspect includes a nut box insert comprising a bottom wall mounted in the housing for sealing an open bottom of the housing, the open bottom defined by inside surfaces of the opposing sides and inside surfaces of the opposing ends, the housing and the nut box insert comprising a nut box, and a nut defining a threaded hole slidably mounted in the nut box, the nut box for constraining rotation of the nut for the threaded hole in the nut to receive a threaded fastener through the access slot for attaching the concrete panel to the building.

In another aspect the means to seal the gaps are independent of the nut box insert. In another aspect the gaps are sealed by welding the gaps closed. In another aspect the gaps are closed by a sealing agent. In another aspect the gaps are also sealed by the nut box insert. In another aspect the elongate centre portion is substantially flat and the opposing longitudinal sides are substantially parallel to each other and substantially perpendicular to the elongate centre portion. In another aspect the elongate centre portion is substantially flat and the opposing sides extend inwardly from the opposing side edges in mutually divergent relation. In another aspect the opposing ends are substantially parallel to each other and substantially perpendicular to the elongate centre portion. In another aspect the opposing ends extend inwardly from the opposing end edges in mutually divergent relation. In another aspect the end flanges are intermediate the elongate centre portion and the side flanges. In another aspect the opposing sides each have at least one rebar aperture outwardly from the opposing side flanges and the opposing end flanges are located inwardly from the elongate centre portion and outwardly from each rebar aperture. In another aspect the opposing side flanges and the opposing end flanges are substantially parallel with the elongate centre portion. In another aspect the housing is made of plate steel. In another aspect the plate steel is between approximately ⅛ inch and ¼ inch thick. In another aspect the plate steel is approximately 3/16 inch thick. In another aspect the nut box insert is a unitary insert. In another aspect the nut box insert has end walls for sealing the gaps between the sides and the ends. In another aspect the nut box insert has side walls and end walls that extend from the bottom wall of the nut box insert to an inner surface of the elongate centre portion. In another aspect the nut box insert further comprises a top wall defining a nut box insert slot in register with the access slot, the nut box insert being resiliently deformable for loading the nut box insert with the nut before the nut box insert is mounted in the housing. In another aspect the nut box insert is a compound insert. In another aspect the bottom wall of the nut box insert carries a resilient layer for sealing the open bottom of the housing and for sealing the gaps between the sides and the ends. In another aspect the nut box insert is held in place by one of the group consisting of supports formed in the longitudinal sides, supports formed in the lateral ends, fastening to the lateral flanges, a friction fit, and gluing. In another aspect the nut is held in biasing contact with the nut box for selectively positioning the threaded hole in the nut along the access slot. In another aspect the nut is held in biasing contact with the nut box by a nut biasing spring between the nut and the bottom wall of the nut box insert. In another aspect the nut is held in biasing contact with the nut box by the resilient layer. In another aspect each opposing end flange comprises at least one form mounting hole. In another aspect each opposing side flange comprises at least one form mounting hole. In another aspect the side flanges or end flanges comprise one or more stud apertures. In another aspect the side flanges or end flanges comprise one or more studs extending inwardly from the side flanges or the end flanges. In another aspect the housing is made from plate metal which forms the housing.

In another aspect any of the above aspects of the inventive concrete insert may have means for sealing the access slot in the elongate centre portion during casting. In one aspect such means for sealing the access slot comprises an access slot cover mounted substantially flush with the upper attachment surface of elongate centre portion for mounting of the concrete insert to a form wherein the access slot cover is removed prior to attachment of the panel to the building.

In another aspect the invention provides a concrete wall panel for attachment to a building comprising a plurality of the concrete inserts of any of the above aspects.

BRIEF DESCRIPTION OF THE DRAWINGS

Certain embodiments of the invention are illustrated with reference to the accompanying drawings, by way of example only and without limiting other embodiments of the invention that would be understood by those skilled in the art, wherein:

FIG. 1 is a perspective view of a first embodiment of the concrete insert.

FIG. 2 is a top plan view of the first embodiment of the concrete insert.

FIG. 3 is a sectional side view of the first embodiment of the concrete insert taken along line 3-3 of FIG. 2.

FIG. 4 is an end view of the first embodiment of the concrete insert.

FIG. 5 is a bottom plan view of the first embodiment of the concrete insert.

FIG. 6 is a top plan view of a blank used to form the first embodiment of the concrete insert.

FIG. 7 is a top plan view of a sealing plate of the first embodiment of the concrete insert.

FIG. 8 is a top plan view of a second embodiment of the concrete insert.

FIG. 9 is a sectional side view of the second embodiment of the concrete insert taken along line 9-9 of FIG. 8.

FIG. 10 is a top plan view of a blank used to form the second embodiment of the concrete insert.

FIG. 11 is a perspective view of a third embodiment of the concrete insert.

FIG. 12 is a sectional end view of the third embodiment of the concrete insert taken along line 12-12 of FIG. 11.

FIG. 13 is a sectional side view of the third embodiment of the concrete insert taken along line 13-13 of FIG. 12.

FIG. 14 is a perspective view of the nut box insert of FIGS. 12 and 13.

FIG. 15 is a sectional end view of a fourth embodiment of the concrete insert taken along line 12-12 of FIG. 11.

FIG. 16 is a sectional side view of the fourth embodiment of the concrete insert taken along line 16-16 of FIG. 15.

FIG. 17 is a perspective view of the nut box insert of the fourth embodiment of the concrete insert.

FIG. 18 is a perspective view of a prior art concrete insert.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Certain preferred embodiments of the invention are described below with reference to the accompanying drawings, wherein identical parts of different embodiments have the same reference numerals. Orientation references relate to the concrete insert as it would be cast in a concrete wall panel, and the wall panel being vertically attached to a building, it being understood that the concrete insert could be used in other orientations. In particular the term outer shall refer to elements closer to the intended inside surface of the pre-cast concrete wall panels, and the term inner shall refer to elements further away from the intended inside surface of the pre-cast concrete wall panels (that is mounted deeper in the concrete of the panels from the inside surface of the panels). The terms outwardly and inwardly have corresponding meanings. In relation to concrete wall panels inside surface means that surface of the wall panels that form the inside surfaces of building walls. The terms inside and outside do not have corresponding meanings to the terms inner and outer, and the terms inside and outside shall have appropriate meanings as the context permits or requires.

The improvements herein to the prior art are best understood by reference to FIG. 18 which is a prior art concrete insert. Prior art concrete insert 19 comprises a housing having an elongate centre portion 22 and longitudinal sides 32 depending from our longitudinal bend lines 30 and extending to inner longitudinal bend lines 36. Longitudinal flanges 34 depend from inner longitudinal bend lines 36 transverse to longitudinal sides 32 and extending in mutually divergent relation. Longitudinal sides 32 have rebar apertures 38. Elongate centre portion 22 has access slot 24 with access slot cover 20 a (not shown in FIGS. 1-17 for clarity). Access slot cover 20 a covers access slot 24 when the concrete insert is attached to the form in which concrete panels are cast and left in access slot 24 until the concrete hardens and the form is removed. Access slot cover 20 a may then be removed anytime prior to mounting of the concrete panel to the building. Prior art concrete insert 19 has a prior art insert 19 a defining a concrete free nut box or channel comprising a nut 96 and biasing spring 100 with the nut box. FIG. 18 shows atypical metal prior art housing 19 b with open bottom and open ends covered by prior art 19 a. Prior art insert 19 a comprises non-structural end caps to prevent concrete from entering the nut box, and insert 19 a has non-structural plastic surface flanges for attaching the concrete inset to a concrete form. However, this arrangement offers no additional pull out resistance.

With respect to the following embodiments of the invention, it is to be understood that the inventive concrete insert would usually be sold with an access slot cover installed therein, however such access slot covers may be sold separately, and installed as required. Such access slot covers could also be reusable. Alternatively, the user may supply their own means for sealing the access slot before casting, such as the application of a strip of duct tape over the elongate centre portion. However, preferably a plastic access slot cover is mounted in the access slot during manufacture, such as by a friction fit, for removal after casting. Prior art access slot cover 20 a as shown in FIG. 18 is not shown in FIGS. 1-17 for clarity.

FIG. 1 is a perspective view of the first embodiment 20 of the concrete insert. Concrete insert 20 has a substantially flat elongate center portion 22, having an outer attachment surface 22 b which is intended to be substantially flush with the inside surface of a concrete wall panel. Elongate centre portion 22 is longitudinally bounded by substantially parallel outer longitudinal bend lines 30 and is laterally bounded by substantially parallel outer lateral bend lines 40, and has a longitudinally oriented access slot 24 therebetween for the insertion of a threaded fastener, usually a bolt or threaded rod (not shown).

Opposing longitudinal sides 32 depend inwardly from outer longitudinal bend lines 30 (preferably in mutually divergent relation, although opposing longitudinal sides 32 may be parallel to each other for example), to inner longitudinal bend lines 36 (preferably parallel to outer longitudinal bend lines 30), and terminate at transverse opposing longitudinal flanges 34 depending from inner longitudinal bend lines 36 and extending in mutually divergent relation (preferably parallel to elongate centre portion 22). Opposing longitudinal sides 32 are delineated from longitudinal flanges 34 by inner longitudinal bend lines 36. Longitudinal sides 32 have opposing edge surfaces 35 defined by elongate centre portion, inner longitudinal bend lines and the thickness of the plate steel used to make the housing 21, which edge surfaces 35 are substantially parallel to outer lateral bend lines 40.

Opposing lateral ends 42 depend inwardly from outer lateral bend lines 40, parallel to and substantially flush with edge surfaces 35 at mating surfaces 43, to inner lateral bend lines 46 (preferably parallel to outer lateral bend lines 40), and terminate with transverse opposing lateral flanges 44 depending from inner lateral bend lines 46 and extending in mutually divergent relation (preferably parallel to elongate center portion 22). Opposing lateral ends 42 are delineated from opposing lateral flanges 44 by inner lateral bend lines 46.

A sealing plate 50 is attached to the bottom of lateral flanges 44 by conventional means such as riveting, bolting, welding or the like which carries on its outer surface a foam friction pad 33, which together form a nut box insert, to form a substantially sealed compartment defining the nut box, located above rebar apertures 38. Inner lateral bend lines 46 provide longitudinal strength to lateral flanges 44 and lateral ends 42, which are supported by edge surfaces 35 of longitudinal sides 32 along end surfaces 43 of lateral ends 42 to resist deformation of lateral ends 42 and lateral flanges 44. Sealing plate 50 further reinforces lateral flanges 44 to further resist deformation of lateral ends 42 and lateral flanges 44 under working loads. Foam friction pad 33 need not necessarily be made of foam but can be made of any resilient layer capable to seal the open bottom of housing.

A nut 26 is slideably mounted in the nut box on the foam friction pad 33 that is carried by sealing plate 50. The preferably square nut 26 is supported in sliding frictional engagement along the inner plane of foam friction pad 33 being substantially parallel with the outer plane of elongate centre portion 22. Again, foam friction pad 33 may be any resilient layer capable of slidably biasing nut 26 against the inside surface 22 a of elongate centre portion 22. Foam friction pad 33 has enlarged end portions which seal gaps between mating surfaces 43 and edge surfaces 35 against the entry of wet cement into the nut box during casting of concrete panels. Foam pad end portions may also be sized to ensure that threaded hole 28 of nut 26 is always under access slot 24. Nut 26 is readily longitudinally repositioned in nut box 27 by finger or other pressure. It is to be understood that preferably square nut 26 need not be square but may be in any shape to engage the inside surfaces of 31 of longitudinal sides 32 to constrain the nut 26 from turning upon receiving a threaded fastener through access slot 24.

Longitudinal flanges 34 may be provided with stud apertures 49 or form mounting holes (not shown). Alternatively the stud apertures 49 may be used as nail holes for attaching concrete insert 20 to a form (not shown) for the casting of a concrete panel 23 (as shown in FIG. 4). Lateral flanges 44 may have studs 52 inwardly attached thereto (not shown). Lateral flanges 44 and sealing plate 50 may contain stud apertures 47 and form mounting holes 48 for attaching concrete insert 20 to a conventional wooden form (not shown) for the casting of a conventional pre-cast concrete panel 23 (as shown in FIG. 4).

FIG. 2 is a top plan view of the first embodiment of the concrete insert 20. Square nut 26 is shown in nut box 27 below the inner surface of elongate center portion 22 a of Housing 21 such that square nut 26 is allowed to slide longitudinally under friction while the inside opposing inside surfaces 31 of longitudinal sides 32 prevent nut 26 from turning when threaded hole 28 is engaged by a corresponding attaching bolt or other threaded fastener such as a threaded rod (not shown). Foam friction pad 33 is shown below nut box 27. Sealing plate 50 below foam friction pad 33 and lateral flanges 44 is not shown in FIG. 2. Opposing longitudinal sides 32 are shown inwardly diverging from each other from outer longitudinal bend lines 30, which is preferred for greater pull out resistance, but need not so diverge. For example, longitudinal sides 32 may be parallel to each other and perpendicular to elongate centre portion 22. Longitudinal sides 32 are shown with rebar apertures 38 and longitudinal flanges 34 are shown with stud apertures 49. Longitudinal sides 32 transition into longitudinal flanges 34 through inner longitudinal bend lines 36.

Lateral ends 42 are shown depending from outer lateral bend lines 40. This first embodiment of concrete insert 20 has edge surfaces 35 which are substantially parallel to each other and outer lateral bend lines 40. Mating surfaces 43 are shown flush with edge surfaces 35. Lateral ends 42 are shown terminating at lateral flanges 44. Lateral flanges 44 may have stud apertures 47 and form mounting holes 48.

FIG. 3 is a sectional side view of the first embodiment of the concrete insert 20 taken along line 3-3 of FIG. 2. Nut 26 with threaded hole 28 is shown frictionally engaged in nut box 27. Foam friction pad 33 is shown under nut 26, and bounding the longitudinal ends of nut box 27. In this embodiment such foam ends are required to seal the gaps between edge surfaces 35 and mating surfaces 43 (unless other sealing means are used). Where such foam ends are so used it is preferable to size the ends to keep threaded hole 28 under access slot 24 in elongate center portion 22. Concrete insert 20 is shown embedded in concrete panel 23 such that the outer attachment surface 22 b of substantially flat elongate center portion 22 is flush with the inside surface of concrete panel 29.

Lateral ends 42 are shown depending inwardly from outer lateral bend lines 40 and transitioning through inner lateral bend lines 46 into lateral flanges 44. Lateral flanges 44 and sealing plate 50 may have stud apertures 47 and form mounting holes 48 (not shown in FIG. 3). Edge surfaces 35 are shown substantially flush with mating surfaces 43. Sealing plate 50 is shown attached to the bottom of lateral flanges 44 (preferably by spot welding) and enclosing the open bottom 41 of housing 21 above rebar aperture 38 and longitudinal flanges 34. Once again, longitudinal flanges 34 may have stud apertures 49.

FIG. 4 is an end view of the first embodiment of concrete insert 20 showing nut 26, threaded hole 28, nut box 27, and foam friction pad 33. The diameter of threaded hole 28 is shown as smaller than the width of access slot 24 in elongate center portion 22 to accommodate a threaded fastener, such as a bolt or threaded rod (not shown). Longitudinal sides 32 are shown depending from elongate center portion 22 at outer longitudinal bend lines 30 with longitudinal sides 32 transitioning through inner longitudinal bend lines 36 into longitudinal flanges 34 which may have stud apertures 49. Lateral ends 42 (shown in FIG. 3) depend from outer lateral bend lines 40 transitioning through inner lateral bend lines 46 into lateral flanges 44. Sealing plate 50 is shown mounted to the bottom of lateral flanges 44 carrying foam friction pad 33 together forming nut box 27 for sealing the open bottom 41 of housing 21 between the opposing inside surfaces 31 of longitudinal sides 32 and the opposing inside surfaces 45 of lateral ends 42 above rebar apertures 38. Lateral flanges 44 may have stud apertures 47 or studs (not shown) and may have form mounting holes 48 or other means for attaching insert 20 to a concrete form (not shown).

Insert 20 is shown embedded in concrete panel 23 with the outer attachment surface 22 b of substantially flat elongate center portion 22 substantially flush with inside surface 29 of concrete panel 23. FIG. 4 also shows a piece of rebar 25 extending through rebar apertures 38 above longitudinal flanges 34.

FIG. 5 is a bottom view of the first embodiment of the concrete insert 20 showing sealing plate 50 attached to the bottom of lateral flanges 44 and together with foam friction pad 33 (not shown in FIG. 5) sealing the open bottom 41 of housing 21 above rebar apertures 38 and longitudinal flanges 34. Longitudinally opposing mating surfaces 43 of lateral ends 42 are shown substantially parallel to each other and substantially flush with edge surfaces 35. Access slot 24, nut 26, nut box 27, and threaded hole 28 are shown in the background in dashed lines.

FIG. 6 is a top view of a blank used to form the first embodiment of concrete insert 20. To form housing 21 from blank 39 bend lateral ends 42 inwardly from elongate center portion 22 at opposing outer lateral bend lines 40 until the lateral ends 42 are parallel to each other and perpendicular to elongate centre portion 22. Bend lateral flanges 44 substantially parallel to the outer attachment surface 22 b of substantially flat elongate center portion 22 in mutually divergent relation. Bend longitudinal sides 32 inwardly from elongate center portion 22 along outer longitudinal bend lines 30 until edge surfaces 35 are substantially flush with mating surfaces 43 of lateral ends 42. Bend longitudinal flanges 34 substantially parallel to the outer attachment surface 22 b of substantially flat elongate center portion 22 in mutually divergent relation. Nut 26 is then mounted against the inner surface 22 a of elongate center portion 22 under access slot 24, followed by foam friction pad 33 followed by sealing plate 50 as shown in FIG. 4.

FIG. 7 is a top view of the sealing plate 50 of the first embodiment showing stud apertures 47 and form mounting holes 48.

FIG. 8 is a top view of the second embodiment of the concrete insert 60. Square nut 26 with threaded hole 28 is shown in nut box 27 under the inner surface of elongate center portion 22 a of housing 21, such that square nut 26 is allowed to slide longitudinally under friction from friction foam pad 33 while the opposing inside surfaces of longitudinal sides 31 a prevent nut 26 from rotating when threaded hole 28 is engaged by a threaded fastener (not shown). Foam friction pad 33 a is shown below nut box 27 followed by sealing plate 50 a which is attached to lateral flanges 44 a. Opposing longitudinal sides 32 a are shown depending inwardly from outer longitudinal bend lines 30 a in mutually divergent relation, which is preferred for greater pull out resistance but need not be so angled. For example, longitudinal sides may be parallel to each other. Longitudinal sides 32 a are shown with rebar apertures 38 and longitudinal flanges 34 a are shown with stud apertures 49. Longitudinal sides 32 a transition into longitudinal flanges 34 a through inner longitudinal bend lines 36 a. Lateral ends 42 a are shown depending from outer lateral bend lines 40 a. This second embodiment of concrete insert 60 has longitudinal sides 32 a having edge surfaces 35 a defined by elongate centre portion 22, longitudinal flanges 34 a and the thickness of the longitudinal sides 32 a, which longitudinal sides 32 a depend inwardly from inner surface 22 a of elongate centre portion 22 at an obtuse angle and preferably approximately 45° from perpendicular to elongate centre portion 22. Mating surfaces 43 a of lateral ends 42 a are shown substantially flush with edge surfaces 35 a. Lateral ends 42 a transition into lateral flanges 44 a through inner lateral bend lines 46 a. Lateral flanges 44 a may have stud apertures 47 and form mounting holes 48.

FIG. 9 is a sectional side view of the second embodiment of concrete insert 60 taken along line 9-9 of FIG. 8. Nut 26 with threaded hole 28 is shown frictionally engaged in nut box 27. Foam friction pad 33 a is shown under nut 26 and bounding the longitudinal ends of nut box 27. In this embodiment such foam ends seal the gaps 37 a between edge surfaces 35 a and mating surfaces 43 a (although other sealing means may be used). Where enlarged foam ends are so used to seal gaps 37 a it is preferable to size the ends to keep threaded hole 28 of nut 26 under access slot 24 in elongate center portion 22. Concrete insert 60 has a substantially flat elongate center portion 22 having an outer attachment surface 22 b which is substantially flush with inside surface of concrete panel 29 (not shown). Lateral ends 42 a are shown depending from outer lateral bend lines 40 a and transitioning through inner lateral bend lines 46 a into lateral flanges 44 a. Lateral flanges 44 a and sealing plate 50 a may have stud apertures 47 and form mounting holes 48 (not shown in FIG. 9). Edge surfaces 35 a are shown substantially flush with mating surfaces 43 a. Sealing plate 50 a is shown attached to the bottom of lateral flanges 44 a and substantially covering open bottom 41 a of housing 21 a above rebar apertures 38 and longitudinal flanges 34 a. Longitudinal flanges 34 a may have stud apertures 49 or studs 52 (both not shown in FIG. 9.).

FIG. 10 is a top view of a blank 39 a used to form the second embodiment of concrete insert 60. To form housing 21 a from blank 39 a lateral ends 42 a are bent inwardly from elongate center portion 22 along outer lateral bend lines 40 a until mating surfaces 43 a of lateral ends 42 a are positioned to be substantially flush with edge surfaces 35 a. To form lateral flanges 44 a lateral sides 42 a are bent along inner lateral bend lines 46 a. Longitudinal sides 32 a are bent inwardly from elongate center portion 22 along outer longitudinal bend lines 30 a until edge surfaces 35 a are substantially flush with mating surfaces 43 a. To form longitudinal flanges 34 a longitudinal sides 32 a are bent along inner longitudinal bend lines 36 a. Nut 26 is then mounted against the inner surface of elongate center portion 22 a under access slot 24, followed by foam friction pad 33 a followed by sealing plate 50 a (as shown in FIG. 9).

FIG. 11 is a perspective view of housing 102 of the third embodiment 80 and the fourth embodiment 120 of the concrete insert. Housing 102 is the same as housing 21 except that the open bottom 41 of housing 102 defined by the inside surfaces of longitudinal sides 31 b and the inside surfaces of lateral ends 45 is sealed by inserting either partial wall nut box insert 84 (as shown in FIG. 14) or enclosed nut box insert 130 (as shown in FIG. 17). Other designs of nut box inserts with a bottom wall 90 for sealing the open bottom 41 of housing 102 may be used (with means for sealing gaps 37 being part of the nut box insert or separate from the nut box insert). In embodiments three and four, bottom wall 90 (of nut box insert 84 or 130) is supported by two nut box insert supports 82 projecting from the inside surface 31 b of each longitudinal side 32 b of housing 102 of embodiment three 80 and embodiment four 120. Preferably a support is located proximate each end of each longitudinal side 32 b. Preferably nut box insert supports 82 are formed by deforming the longitudinal sides 32 b of housing 102 by metal punching or similar procedure. Those skilled in the art will recognize that nut box insert supports 82 may be attached to or form part of housing 102 in a number of ways including welding, gluing, and the like. Those skilled in the art will also appreciate that nut box insert supports 82 need not be in opposing longitudinal sides 32 b. For example, nut box insert supports 82 may be formed in lateral ends 42 or lateral flanges 44. Those skilled in the art will also recognize that one pair of opposing nut box insert supports 82 or one support 82 in each opposing longitudinal side 32 b or one support 82 in each opposing lateral end 42 may suffice. Such supports 82 need not themselves be opposing each other if in opposing sides or ends. Those skilled in the art will also recognize that nut box inserts such as partial wall nut box insert 84 and enclosed nut box insert 130 need not require mechanical supports. For example, a nut box insert 84 or 130 may be glued or bonded in place or held in place via a friction fit especially a friction fit between parallel opposing lateral ends 42 not angled outwardly from each other. Similarly, if longitudinal sides of a housing are substantially parallel then this would accommodate a friction fit as well. Those skilled in the art will also recognize that a friction fit or snap fit may be accomplished a number of ways. Those skilled in the art will also recognize that housing 21 a of the second embodiment 60 may be used with a cooperating nut box insert by modifying nut box insert 84 or nut box insert 130 by extending the length of bottom wall 90 and angling end walls 86 inwardly (towards inner surface of elongate centre portion 22 a) from bottom wall 90 in converging relation.

Partial wall nut box insert 84 of embodiment three 80 or enclosed nut box insert 130 of embodiment four 120 are not shown in FIG. 11 for clarity. Similarly, nut biasing spring 100 of embodiments three 80 and four 120 are not shown in FIG. 11, nor is spring recess 98 of nut 96.

FIG. 12 is a sectional end view of the third embodiment 80 of the concrete insert of FIG. 11 taken along the line 12-12 of FIG. 11. FIG. 12 shows partial wall nut box insert 84 supported under bottom wall 90 by nut box insert supports 82 in longitudinal sides 32 b of housing 102. Partial side walls 88 mate with the inside surfaces of longitudinal sides 31 b. Accordingly the inner surface of the elongate centre portion 22 a, the inside surfaces of longitudinal sides 31 b and the inside surfaces of partial side walls 88 and the inside surface of bottom wall 90 of partial wall nut box insert 84 define nut box 81 of the third embodiment 80. The inside surfaces of partial side walls 88 provide clearance from each other in order for nut biasing spring 100 to slide freely longitudinally along nut box 81. Nut biasing spring 100 is mounted in spring recess 98 in the inner surface of nut 96 which biases nut 96 against the inner surface of elongate centre portion 22 a such that when threaded hole 28 of nut 96 is engaged by a threaded bolt or rod (not shown) through access slot 24 sliding of said bolt or rod through access slot 24 causes the combination of nut 96 and recessed nut biasing spring 100 to travel in unison longitudinally through nut box 81 of the third embodiment 80.

An outer surface (of end walls) 87 of end walls 86 (of partial wall nut box insert 84) extends from partial side walls 88 and mates with the inside surface of longitudinal sides 31 b and the inner surface of elongate centre portion 22 a proximate lateral ends 42 (not shown in FIG. 12) to seal nut box 81 from the seepage of wet concrete (through the gaps 37 between edge surfaces 35 and mating surfaces 43, all not shown in FIG. 12). The mating of the inside surfaces of longitudinal sides 31 b of housing 102 and partial side walls 88 of partial wall nut box insert 84 prevents the seepage of wet concrete through the otherwise open bottom 41 of housing 102 into nut box 81. The outer surfaces of end walls 87 and/or the outside surfaces of partial side walls 88 may be adapted to include raised end wall and side wall sealing beads 92, 94 (shown in FIG. 14) to aid in the sealing of nut box 81 against wet concrete present during the formation of concrete panels.

FIG. 13 is a sectional side view of the third embodiment 80 of the concrete insert shown in FIG. 12 taken along line 13-13 (of FIG. 12) which shows outer surfaces of end walls 87 mating with the inner surface of elongate centre portion 22 a. FIG. 13 is shown without nut 96 or nut biasing spring 100 for clarity. Partial side wall 88 is shown extending from bottom wall 90 of partial wall nut box insert 84 with bottom wall 90 being supported by nut box insert supports 82 of longitudinal sides 32 b above rebar apertures 38 and longitudinal flanges 34. The inner surface of bottom wall 90 of nut box insert 84 may, but need not be, flush with the inner surface of lateral flanges 44. Those skilled in the art will also recognize that there would be substantially no gaps between the inside surfaces of lateral ends 42 and the outside surfaces of the ends of partial wall nut box insert 84 if partial wall nut box insert 84 is mounted in housing 102 via a friction fit between said lateral ends 42 in which case the outside surface of end walls 87 would seal the nut box 81.

FIG. 14 is a perspective view of the partial wall nut box insert 84 having end walls 86 with outer surfaces of end walls 87 which in turn may have sealing beads 92. Partial wall nut box insert 84 also has partial side walls 88 and bottom wall 90. Partial side walls 88 may also have sealing beads 94.

FIG. 15 is a sectional side view of housing 102 of FIG. 11 showing concrete insert 120 of the fourth embodiment. In this fourth embodiment housing 102 is the same as in the third embodiment 80 but supports enclosed nut box insert 130 in the same way that housing 102 supports partial wall nut box 84. The alternative means for mounting nut box 84 in the open bottom 41 of housing 102 in the third embodiment 80 also applies to enclosed nut box insert 130 of the fourth embodiment. In this fourth embodiment nut box 121 is defined by top wall 124, bottom wall 90, full side walls 122 and end walls 86. Enclosed nut box insert 130 has nut box insert slot 126 in top wall 124, which nut box insert slot 126 should be wide enough, or deformable enough, to allow a threaded bolt or rod inserted through access slot 24 in housing 102 to pass through nut box insert slot 126 to enter threaded hole 28 in nut 96. In this fourth embodiment 120 the end walls 86 and full side walls 122 of enclosed nut box insert 130 seal nut box 121. The same principles apply to the second embodiment, as well as the third embodiment. Top wall 124 of enclosed nut box insert 130 mates with the inner surface 22 a of elongate centre portion 22 to further guard against wet concrete seeping into the nut box 121 through gaps 37 (not shown in FIG. 15). In this case, the outer surface of nut 96 may slide along the inner surface of top wall 124 of enclosed nut box insert 130. In this embodiment that portion of top wall 124 of enclosed nut box insert 130 between the outer surface of nut 96 and the inner surface 22 a of elongate centre portion 22 is compressed in which instance the compressed portion of top wall 124 may act as a lock washer. Alternatively, nut box insert slot 126 may be widened to accommodate the full width of nut 96 in which case nut 96 would bear directly against the inner surface 22 a of elongate centre portion 22, and top wall 124 would not be compressed in use.

In manufacture where nut box insert slot 126 is narrower than the thickness of nut 96, nut box insert slot 126 of enclosed nut box insert 130 may be temporarily deformed to receive the assembly of nut with spring recess 96 and nut biasing spring 100, which are mounted in enclosed nut box insert 130 prior to mounting the assembled enclosed nut box insert 130 into the open bottom 41 of housing 102.

FIG. 16 is a sectional side view of the fourth embodiment 120 of the concrete insert taken along line 16-16 of FIG. 15. FIG. 16 also shows nut box insert supports 82 supporting bottom wall 90 of enclosed nut box insert 130 wherein the top wall 124 of enclosed nut box insert 130 mates with the inner surface of elongate centre portion 22 a. Enclosed nut box insert 130 is shown as bounded by top wall 124, bottom wall 90 and end walls 86 and full side walls 122. Enclosed nut box insert 130 also has nut box insert slot 126 in top wall 124. It will be appreciated by those skilled in the art that full side walls 122 may be substantially parallel if opposing longitudinal sides 32 b of a corresponding housing are also substantially parallel, in which case enclosed nut box insert 130 may be mounted in the open bottom 41 of housing 102 using a friction fit between said parallel longitudinal sides (not shown). A friction fit may also be used between parallel lateral ends. Those skilled in the art will also recognize that enclosed nut box insert 130 may be provided with angled ends corresponding to the angulation of lateral ends 42 a of the second embodiment of the concrete insert herein for use with a corresponding housing. Those skilled in the art will also appreciate that enclosed nut box insert 130 need not necessarily have the same shape as the open bottom 41 of corresponding housing 102 as long as top wall 124 is securely mated against inner surface of elongate centre portion 22 a.

FIG. 17 is a perspective view of the enclosed nut box insert 130 having end walls 86, side walls 122, bottom wall 90 and top wall 124, top wall 124 defining nut box insert slot 126. Bottom wall 90 is supported by nut box insert supports 82 for insert 130 to seal the open bottom 41 of housing 102, and for sealing gaps 37, unless gaps 37 are separately sealed.

The above embodiments are to be understood as examples and not as limiting the scope of the invention.

PARTS LIST

-   19. Prior art concrete insert -   19 a. Prior art plastic insert -   19 b. Prior-art housing (of Prior Art Concrete Insert) -   20. First embodiment of the concrete insert -   20 a. Access slot cover -   21. Housing (of first embodiment) -   21 a. housing (of second embodiment) -   22. Elongate centre portion -   22 a. Inner surface of elongate centre portion -   22 b. Outer attachment surface (of elongate centre portion) -   23. Concrete panel -   24. Access slot -   25. Rebar -   26. Nut -   27. Nut box (of first and second embodiments) -   28. Threaded Hole (in nut) -   29. Inside surface of concrete panel -   30. Outer longitudinal bend lines (delineating the elongate centre     portion from longitudinal sides of first embodiment) -   30 a. Outer longitudinal bend lines (delineating the elongate centre     portion from longitudinal sides of second embodiment) -   31. Inside surface of longitudinal sides (of housing of first     embodiment) -   31 a. Inside surface of longitudinal sides (of housing of second     embodiment) -   31 b. Inside surface of longitudinal sides (of housing of third and     fourth embodiments) -   32. Longitudinal sides of housing (of first embodiment) -   32 a. Longitudinal sides of housing (of second embodiment) -   32 b. Longitudinal sides of housing (of third and fourth     embodiments) -   33. Foam friction pad (of first embodiment) -   33 a. Foam friction pad (of second embodiment) -   34. Longitudinal flanges (of first, third and fourth embodiments) -   34 a. Longitudinal flanges (of second embodiment) -   35. Edge surfaces (of sides of longitudinal sides of first, third     and fourth embodiments) -   35 a. Edge surfaces (of sides of longitudinal sides of second     embodiment) -   36. Inner longitudinal bend lines (delineating longitudinal sides     from longitudinal flanges of first, third and fourth embodiments) -   36 a. Inner longitudinal bend lines (delineating longitudinal sides     from longitudinal flanges of second embodiment) -   37. Gaps (between edge surfaces and mating surfaces) -   37 a. Gaps (between edge surfaces and mating surfaces of second     embodiment) -   38. Rebar apertures -   39. Blank for first embodiment of housing -   39 a. Blank for second embodiment of housing -   40. Outer lateral bend lines (delineating elongate centre portion     from lateral ends of first, third and fourth embodiments) -   40 a. Outer lateral bend lines (delineating elongate centre portion     from lateral ends of second embodiment) -   41. Open bottom (of housing of first, third and fourth embodiments) -   41 a. Open bottom (of housing of second embodiment) -   41 b. Open bottom (of prior art concrete insert) -   42. Lateral ends of housing (of first, third and fourth embodiments) -   42 a. Lateral ends of housing (of second embodiment) -   43. Mating surfaces (of lateral ends of first, third and fourth     embodiments) -   43 a. Mating surfaces (of lateral ends of second embodiment) -   44. Lateral flanges (of first, third and fourth embodiments) -   44 a. Lateral flanges (of second embodiment) -   45. Inside surfaces of lateral ends -   46. Inner lateral bend lines (delineating lateral ends and lateral     flanges of first, third and fourth embodiments) -   46 a. Inner lateral bend lines (delineating lateral ends and lateral     flanges of second embodiment) -   47. Stud apertures (in end flanges and sealing plate) -   48. Form mounting holes (in end flanges) -   49. Stud apertures (in longitudinal flanges) -   50. Sealing plate -   50 a. Sealing plate (of second embodiment) -   52. Stud -   60. Second embodiment of concrete insert -   80. Third embodiment of concrete insert -   81. Nut box (of third embodiment) -   82. Nut box insert supports (of third and fourth embodiments) -   84. Partial wall nut box insert -   86. End walls (of nut box insert) -   87. Outer surface of end walls (of nut box insert) -   88. Partial side walls (of nut box insert) -   90. Bottom wall (of nut box insert) -   92. Sealing bead (of end walls) -   94. Sealing bead (of side walls) -   96. Nut with spring recess -   98. Spring recess (of nut) -   100. Nut biasing spring -   102. Housing (with nut box insert supports) -   120. Fourth embodiment of concrete insert -   121. Nut box (of fourth embodiment) -   122. Full side wall (of nut box insert) -   124. Top wall (of nut box insert) -   126. Nut box insert slot -   130. Enclosed nut box insert 

1. A concrete insert for casting in a concrete wall panel having an inside surface for attachment to a building, comprising: a housing having an elongate centre portion, two opposing longitudinal sides, two opposing lateral ends, two opposing longitudinal flanges, and two opposing lateral flanges; the elongate centre portion, bounded by opposing outer longitudinal bend lines and by opposing outer lateral bend lines, and having an outer attachment surface for mounting the elongate centre portion substantially flush with the inside surface of the concrete wall panel, the elongate centre portion defining a longitudinally oriented access slot; the opposing longitudinal sides depending inwardly from the opposing outer longitudinal bend lines to opposing inner longitudinal bend lines and having opposing edge surfaces defined by the elongate centre portion, the longitudinal flanges and the thickness of the longitudinal sides; the opposing longitudinal flanges depending from opposing inner longitudinal bend lines transversely to the opposing longitudinal sides and extending in mutually divergent relation; the opposing lateral ends depending inwardly from the opposing outer lateral bend lines to the opposing inner lateral bend lines and having opposing mating surfaces on the inside surfaces of each of the lateral ends for mating substantially flush with the opposing edge surfaces of each longitudinal side; the opposing lateral flanges depending from the opposing inner lateral bend lines transversely to the opposing lateral ends and extending in mutually divergent relation; a nut box insert comprising a bottom wall mounted in the housing for sealing an open bottom of the housing, the open bottom defined by inside surfaces of the opposing longitudinal sides and inside surfaces of the opposing lateral ends, and for sealing the gaps between the edge surfaces and the mating surfaces; the housing and the nut box insert comprising a nut box; and a nut defining a threaded hole slidably mounted in the nut box, the nut box for constraining rotation of the nut for the threaded hole in the nut to receive a threaded fastener through the access slot for attaching the concrete wall panel to the building.
 2. The concrete insert of claim 1 wherein the elongate centre portion is substantially flat and the opposing longitudinal sides are substantially parallel to each other and substantially perpendicular to the elongate centre portion.
 3. The concrete insert of claim 1 wherein the elongate centre portion is substantially flat and the opposing longitudinal sides depend inwardly from the opposing outer longitudinal bend lines in mutually divergent relation.
 4. The concrete insert of any one of claims 1-3 wherein the opposing lateral ends are substantially parallel to each other and substantially perpendicular to the elongate centre portion.
 5. The concrete insert of any one of claims 1-3 wherein the opposing lateral ends depend inwardly from the opposing outer lateral bend lines in mutually divergent relation.
 6. The concrete insert of any one of claims 1-3 wherein the lateral flanges are intermediate the elongate centre portion and the longitudinal flanges.
 7. The concrete insert of any one of claims 1-3 wherein the opposing longitudinal sides each have at least one rebar aperture outwardly from the opposing longitudinal flanges and the opposing lateral flanges are located inwardly from the elongate centre portion and outwardly from each rebar aperture.
 8. The concrete insert of any one of claims 1-3 wherein the opposing longitudinal flanges and the opposing lateral flanges are substantially parallel with the elongate centre portion.
 9. The concrete insert of claim 1 wherein the housing is made of plate steel is between approximately ⅛ inch and ¼ inch thick.
 10. The concrete insert of claim 9 wherein the plate steel is approximately 3/16 inch thick.
 11. The concrete insert of claim 1 wherein the nut box insert has end walls for sealing the gaps between the edge surfaces and the mating surfaces.
 12. The concrete insert of claim 1 wherein the nut box insert is a unitary insert having side walls and end walls that extend from the bottom wall of the nut box insert to an inner surface of the elongate centre portion.
 13. The concrete insert of claim 12 wherein the nut box insert further comprises a top wall defining a nut box insert slot in register with the access slot, the nut box insert being resiliently deformable for loading the nut box insert with the nut before the nut box insert is mounted in the housing.
 14. The concrete insert of claim 1 wherein the bottom wall of the nut box insert carries one or more a resilient layer for sealing the open bottom of the housing and for sealing the gaps between the edge surfaces and the mating surfaces.
 15. The concrete insert of claim 1 wherein the nut box insert is held in place by one of the group consisting of supports formed in the longitudinal sides, supports formed in the lateral ends, fastening to the lateral flanges, a friction fit, and gluing.
 16. The concrete insert of claim 1 wherein the nut is held in biasing contact with the nut box for selectively positioning the threaded hole in the nut along the access slot.
 17. The concrete insert of claim 16 wherein the nut is held in biasing contact with the nut box by a nut biasing spring between the nut and the bottom wall of the nut box insert.
 18. The concrete insert of claim 14 wherein the nut is held in biasing contact with the nut box by the resilient layer.
 19. The concrete insert of claim 1 wherein each opposing lateral flange comprises at least one form mounting hole.
 20. The concrete insert of claim 1 wherein the longitudinal flanges or lateral flanges comprise one or more stud apertures.
 21. The concrete insert of claim 1 wherein the longitudinal flanges or lateral flanges comprise one or more studs extending inwardly from the longitudinal flanges or the lateral flanges.
 22. The concrete insert of claim 1 wherein the housing is made from a blank of plate metal which forms the housing into a predetermined shape when the blank is bent along outer longitudinal bend lines, outer lateral bend lines, inner longitudinal bend lines and inner lateral bend lines.
 23. The concrete insert of claim 22 wherein the housing is made according to a method comprising the following steps:
 1. cut the blank out of the plate metal into the two dimensional shape necessary to form the housing into the desired three dimensional shape;
 2. bend the blank along the inner longitudinal bend lines;
 3. bend the blank along the inner lateral bend lines;
 4. bend the blank along outer longitudinal bend lines;
 5. bend the blank along outer lateral bend lines;
 6. punch the access slot, rebar apertures form mounting holes and stub apertures in the blank.
 24. A concrete insert for casting in a concrete panel having an inside surface for attachment to a building comprising: a housing having an elongate centre portion, two opposing longitudinal sides, two opposing lateral ends, two opposing longitudinal flanges, and two opposing lateral flanges; the elongate centre portion, bounded by opposing outer longitudinal bend lines and by opposing outer lateral bend lines, and having an outer attachment surface for mounting the elongate centre portion substantially flush with the inside surface of the concrete panel, the elongate centre portion defining a longitudinally oriented access slot; the opposing longitudinal sides depending inwardly from the opposing outer longitudinal bend lines to opposing inner longitudinal bend lines; the opposing longitudinal flanges depending from opposing inner longitudinal bend lines transversely to the opposing longitudinal sides and extending in mutually divergent relation; the opposing lateral ends depending inwardly from the opposing outer lateral bend lines to the opposing inner lateral bend lines; the opposing lateral flanges depending from the opposing inner lateral bend lines transversely to the opposing lateral ends and extending in mutually divergent relation; the longitudinal sides and lateral ends defining gaps therebetween; means for sealing the gaps between the longitudinal sides and the lateral ends; a nut box insert comprising a bottom wall mounted in the housing for sealing an open bottom of the housing, the open bottom defined by inside surfaces of the opposing longitudinal sides and inside surfaces of the opposing lateral ends; the housing and the nut box insert comprising a nut box; and a nut defining a threaded hole slidably mounted in the nut box, the nut box for constraining rotation of the nut for the threaded hole in the nut to receive a threaded fastener through the access slot for attaching the concrete panel to the building.
 25. The concrete insert of claim 24 wherein the opposing lateral ends depend inwardly from the opposing outer lateral bend lines in mutually divergent relation.
 26. The concrete insert of claim 24 wherein the lateral flanges are intermediate the elongate centre portion and the longitudinal flanges.
 27. The concrete insert of claim 24 wherein the housing is made of plate steel between approximately ⅛ inch and ¼ inch thick.
 28. The concrete insert of claim 27 wherein the plate steel is approximately 3/16 inch thick.
 29. The concrete insert of claim 24 wherein each opposing lateral flange comprises at least one form mounting hole.
 30. The concrete insert of claim 24 wherein the housing is made from a blank of plate metal which forms the housing into a predetermined shape when the blank is bent along outer longitudinal bend lines, outer lateral bend lines, inner longitudinal bend lines and inner lateral bend lines.
 31. A concrete insert for casting in a concrete panel having an inside surface for attachment to a building, comprising: a housing having an elongate centre portion, two opposing sides, two opposing ends, two opposing side flanges, and two opposing end flanges; the elongate centre portion, bounded by opposing side edges and by opposing end edges, having an outer attachment surface for mounting the elongate centre portion substantially flush with the inside surface of the concrete panel, the elongate centre portion defining a longitudinally oriented access slot; the opposing sides extending inwardly from the opposing side edges to the opposing side flanges; the opposing side flanges extending transversely from the opposing sides and extending in mutually divergent relation; the opposing ends extending inwardly from the opposing end edges to the opposing end flanges; the opposing end flanges extending transversely from the opposing ends and extending in mutually divergent relation; the sides and the ends defining gaps therebetween; means for sealing the gaps between the sides and the ends; a nut box insert comprising a bottom wall mounted in the housing for sealing an open bottom of the housing, the open bottom defined by inside surfaces of the opposing sides and inside surfaces of the opposing ends; the housing and the nut box insert comprising a nut box; and a nut defining a threaded hole slidably mounted in the nut box, the nut box for constraining rotation of the nut for the threaded hole in the nut to receive a threaded fastener through the access slot for attaching the concrete panel to the building.
 32. The concrete insert of claim 31 wherein the opposing ends extend inwardly from the opposing end edges in mutually divergent relation.
 33. The concrete insert of claim 31 wherein the end flanges are intermediate the elongate centre portion and the side flanges.
 34. The concrete insert of claim 31 wherein the housing is made of plate steel between approximately ⅛ inch and ¼ inch thick.
 35. The concrete insert of claim 34 wherein the plate steel is approximately 3/16 inch thick.
 36. The concrete insert of claim 31 wherein each opposing end flange comprises at least one form mounting hole.
 37. The concrete insert of any one of claims 1, 24 and 31, further comprising a removable access slot cover for preventing concrete from entering the nut box during casting of the concrete panels.
 38. A concrete wall panel for attachment to a building comprising the concrete insert of any one of claims 1, 24 and
 31. 